So I know someone who has a recent Audi Q5 told me about using their phone as a car key, so I looked it up a bit. Audi’s site isn’t too clear on how it all works but just as a thought experiment I want to figure out how to clone it to my hand (no, I don’t want to break into their car). At some point when I have a bit more money I’ll probably snag a used Audi with that feature or get a Tesla and hack the shit out of it.
Audi’s site is a bit confusing as it talks about storing an ID in the SIM card and on the device but then go onto say “The Audi connect key is always ready for use, even if the smartphone’s battery is not charged (depends on specific model), because the NFC chip draws the energy it needs from an electromagnetic field produced by its counterpart”
Audi has digitalized the conventional vehicle key and transferred it to the user’s smartphone in the form of the Audi connect key. It is used to unlock, lock and start the car. Communication between the vehicle and the smartphone is by near field communication (NFC). This technology refers to a standard in which data is transmitted over short distances by radio signal. To unlock the car, the driver holds the smartphone near the handle of the driver’s door which contains an NFC antenna. To start the engine, the phone is placed in the Audi phone box, which is also equipped with an NFC antenna.
The highly sensitive data of the digital key in the smartphone must be protected against read-out, duplication and manipulation. To do this, the Audi connect key is saved in a secure memory and execution environment within the smartphone, either on the SIM card or directly in the device. This secure element is connected directly to the NFC antenna via the single wire protocol (SWP) – which is another security advantage, because the smartphone’s operating system is not involved in the communication between the car and the smartphone.
In the future, customers will be able to share up to 15 keys over-the-air, e.g. with family members, friends or colleagues. The car recognizes the key owner when it is unlocked, and it loads a wide variety of settings from the user’s individual profile – ranging from seat position to air conditioning and navigation settings. This solution makes the one-to-one relationship between a vehicle key and a vehicle obsolete, because one smartphone can store keys for multiple vehicles. For situations in which the driver needs to share the Audi connect key for a short period of time, but the driver does not want to hand over the smartphone, an Audi connect key card in credit card format is available in the car. The driver can activate it and give it to valet parking personnel, for instance, or passed on in the case of a breakdown.
The Audi connect key is always ready for use, even if the smartphone’s battery is not charged (depends on specific model), because the NFC chip draws the energy it needs from an electromagnetic field produced by its counterpart.